All Questions
Tagged with beyond-the-standard-model dark-matter
51 questions
2
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1
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407
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Contribution of dark matter to running of physical constants
I read that "essentially everything in the Standard Model impacts the running of every physical constant in the Standard Model. So, if there is even a single particle missing from the Standard ...
- 455
1
vote
0
answers
53
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Equivalence of axion to fermion couplings
In order to solve the Strong CP problem through the axion, we introduce the axion-gluon coupling
$$
\dfrac{a(x)}{f_a} \text{Tr}\, G\tilde{G}.\tag{1}
$$
In a similar fashion, we may introduce the axion-...
- 2,210
1
vote
1
answer
224
views
Does NFW profile work for any galaxy?
We use Navarro–Frenk–White (NFW) to calculate Dark Matter (DM) density. Can we use it for DM halo in any galaxy or is it used only for Milky Way (MW)?
- 11
2
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0
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53
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Slope in interaction strength vs mass for QCD axion
The theory models of QCD axion, i.e. those who solve the strong CP problem, all have a prediction that follows a band with a slope in the space interaction strength vs. axion mass.
(1) What does cause ...
- 585
2
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0
answers
30
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Lifetime of a WIMP [duplicate]
I have been watching videos of WIMP's and have a simple question..
The larger the particles, the shorter their lifetime. A top quark is so massive that it cannot form a "stable" bond with ...
- 2,754
3
votes
1
answer
123
views
Could a fourth family of quarks and leptons account for dark matter?
In the early universe, could a family of quarks and leptons have formed an electrically neutral particle that is dark matter?
user361671
1
vote
1
answer
73
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Classification of elementary particles that have been proposed to explain dark matter
I'd like to write a paragraph about elementary particles that have been proposed to explain dark matter, but I don't know exactly how to classify these particles or arrange them:
Scaler field
-- ...
- 269
1
vote
1
answer
64
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Right-handed neutrinos as dark matter and neutrino bounds
How can right-handed neutrinos evade the SM experimental bound $N_\nu=3$ and become all the dark matter?
- 6,727
0
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0
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132
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Right-handed neutrinos Lagrangian and drawing Feynman diagrams from it
The Lagrangian for the right handed neutrino field is:
$$
L_{\nu} = y_{\alpha i} \bar{L_{\alpha}} H^{\dagger} N_{i} + m_{i} \bar{N^{c}_{i}N_{i}}
$$
With $ L_{\alpha} $ being the left-handed lepton ...
- 53
0
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0
answers
74
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Assuming the announced $g-2$ experiment αμ discrepancy is mainly because a dark matter candidate, is this a quantum gravity induced effect?
The possible effectively extra added vacuum polarization by a dark matter candidate could account for the recently announced anomalous magnetic moment αμ measured discrepancy from the theoretical ...
- 4,366
1
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0
answers
36
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Proposed dark matter mass limits
A recent paper (arXiv version also available) proposes to derive dark matter mass ranges of $10^{-3} \sim 10^{7} eV$ for a singlet scalar, parity-violating pseudoscalar, or spin-2 candidate, $10^{-21}\...
- 990
1
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1
answer
73
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What sort of observations constrain the QCD interactions of dark matter?
Within our current limits of observation, dark matter (DM) is nonluminous i.e., it neither absorbs nor gives off electromagnetic (EM) radiation. This tells that DM is electrically neutral having no EM ...
- 27.2k
3
votes
0
answers
49
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What properties of dark matter can we derive from each of the available methods for probing the physics of dark matter?
This is probably a long shot but it's worth trying. My question is the following:
What properties of dark matter can we derive from each of the available methods for probing the physics of dark matter?...
- 373
1
vote
1
answer
54
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Dark standard model linked though Higgs
is it possible to have a dark std model (ie image of the std model) linked to the std model only through the Higgs? That would allow dark matter condensation, dark galaxies, stars, planets and biology....
- 65
1
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0
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Possibility of reaching equilibrium starting with a nonequilibrium initial condition in the early radiation-domination
Update after @knzhou's comment
If in a theory, the coupling of the dark matter (DM) field to the Standard Model (SM) fields is small enough, the rate of interaction of the DM particles in the ...
- 27.2k
1
vote
0
answers
37
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Is this equality based on the HDM true?
It is stated in Sterile Neutrinos as Dark Matter that in the HDM model: $$\frac{\mu^2}{m_s}= 92 h^2 \text{eV} \tag{1}$$
where $m_s$ represents the mass of sterile neutrinos and $\mu^2$ represents the ...
- 759
2
votes
0
answers
45
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Why would the damping factor of neutrino oscillations be negligible?
In this article the Boltzmann equation for the sterile
neutrinos is simpified to this form:
$$\frac{\partial}{\partial t} f_s (p,t) -H p \frac{\partial}{\partial p} f_s (p,t) \approx \frac{\Gamma_\...
- 759
1
vote
1
answer
500
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What is the relation between energy density ($\Omega$) and the number density of neutrinos ($n$)?
What is the numerical relation between energy density ( $\Omega_\text{s}, \Omega_\alpha$), and the number density of neutrinos (sterile - $n_s$ , active - $n_\alpha$)?
Background info that might help ...
- 759
0
votes
1
answer
97
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Higgs particles and Dark Matter particles
Usually, it is mentioned that the Higgs field IS the origin of mass for known fundamental particles.
If very heavy dark particles are found (heavier or much heavier than the top quark), should it mean ...
- 6,727
4
votes
2
answers
99
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What are ordinary mass-terms (of neutrinos)?
When reading the introduction to Sterile neutrino hot, warm, and cold dark matter I came across the following definition of sterile neutrinos:
We can define sterile neutrinos generically as spin-$\...
- 759
38
votes
1
answer
7k
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Is there any evidence that dark matter interacts with ordinary matter non-gravitationally?
As far as I understand it, dark matter direct detection experiments are based on the idea that dark matter interacts with ordinary matter, it just has a very small cross-section. So far, there's been ...
- 22.1k
6
votes
1
answer
2k
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Obtaining the effective Lagrangian for axions from the spontaneous breakdown of Peccei-Quinn symmetry
I am reading Section $3$ of this review titled The Strong CP Problem and Axions by R. D. Peccei and also the post here.
A famous solution of the Strong CP problem in QCD is offered by the proposal of ...
- 27.2k
1
vote
1
answer
201
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Dark matter in the time window between freeze-out and kinetic decoupling
Background
After the freeze-out, when all annihilations have stopped, the abundance ($Y=\frac{n}{s}$) of thermal dark matter species no longer changes with time. However, it is still kept in kinetic ...
- 27.2k
-3
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2
answers
108
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Dark matter composition [closed]
I assume that dark matter is made of heavy neutrinos.But wouldnt they be converted into neutrinos with less mass throygh weak interaction?So dark matter isnt made of neutrinos.I think there is truly ...
- 27
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1
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95
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Dark matter and supersymmetric particles
Is there a possibility to consider supersymmetric particles of fermions and bosons as the unknown dark matter?
- 260
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2
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592
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If neutrinos are disfavoured as DM candidates why aren't axions?
Numerical simulations of observed large-scale structure formation work best with Cold Dark Matter (CDM; see the answer here). Neutrinos are candidates for Hot Dark Matter (HDM), and hence they cannot ...
- 27.2k
0
votes
1
answer
90
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Like the Higgs sector of the standard model, is there a SUSY sector which is also such a sector?
This question arose from an application of the virial theorem that showed how Bose-Einstein condensates of astrophysical dimension could arise from condensing clouds of normal phase bosons. If these ...
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3
votes
1
answer
1k
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Why is the dark matter freeze-out temperature $T\sim \frac{m}{20}$ so generic?
For a dark matter of mass $m$, the typical freeze-out temperature is $T$ is usually assumed to be between $\frac{m}{20}-\frac{m}{25}$. But the freeze-out temperature depends upon the annihilation ...
- 27.2k
2
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1
answer
99
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Is it sufficient to consider the uncharged dark matter and a $\mathbb{Z}_2$ symmetry to prevent its decay into photons?
Higgs boson, though electrically neutral, can decay to produce a pair of photons i.e., have electromagnetic interactions. See the answer here. Therefore, it appears that making dark matter ...
- 27.2k
0
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1
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193
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Why can't the Higgs vacuum energy clump to galaxies and act as dark matter (instead of dark energy)? [closed]
The Higgs field has a nonzero vacuum expectation value which contributes to the energy density of the Universe. Energies contribute to the curvature of spacetime and affected by gravitational ...
- 27.2k
18
votes
3
answers
3k
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What gives mass to dark matter particles?
Assuming that dark matter is not made of WIMPs (weakly interacting massive particles), but interacts only gravitationally, what would be the possible mechanism giving mass to dark matter particles? If ...
- 12.9k
4
votes
1
answer
248
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How are the dark matter (DM) thermalization rates derived in singlet DM model?
This well-cited paper talks about a minimal renormalizable extension to the Standard Model (SM) to incorporate particle dark matter (DM) into it by adding a real scalar field $S$ which (unlike the ...
- 27.2k
2
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2
answers
496
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Why do we think that the dark sector is simpler?
Matter makes up roughly $5\%$ of the Universe while dark matter makes up roughly $25\%$. For matter and radiation, we have a complicated Standard model with many generations of fermions and various ...
- 27.2k
4
votes
1
answer
212
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About the consequences of $\mathbb{Z}_2$ invariance in dark matter models
This well-cited paper talks about is a minimal renormalizable extension to the Standard Model (SM) to incorporate particle dark matter (DM) into it by adding a real scalar field $S$ which (unlike the ...
- 27.2k
5
votes
2
answers
202
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Why did dark matter interact with the Standard model particles in the early Universe but not now?
In the thermal dark matter (DM) scenario, it is the interaction of the DM particles with the Standard Model (SM) particles that kept the DM particles in kinetic equilibrium with the thermal plasma.
...
- 27.2k
6
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1
answer
531
views
Why is the Standard model Higgs not a candidate of dark matter (in particular, a WIMP)?
Please consider me as a naive self-learner in this field.
The Standard Model (SM) Higgs boson is electrically neutral and has a mass of around $125$ GeV (which lies in the WIMP window i.e., between ...
- 27.2k
4
votes
2
answers
186
views
What are the steps to identify a dark matter candidate?
By looking at the Lagrangian of a simple particle physics model, how do people identify the dark matter (DM) candidates, if any?
One of the criteria is to check whether the electric charge of the ...
- 27.2k
1
vote
2
answers
197
views
Can the centers of galaxies act as particle accelerators?
At the centers of galaxies, the amount of dark matter is much higher than that of ordinary matter. So the centers can effectively gravitationally attract and accelerate ordinary matter- without much ...
- 1,187
3
votes
1
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254
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How did dark matter become a relic?
Why did the decay rate of the dark matter particles fall when the temperature of the Universe $T_U$ dropped below dark matter mass $M_{DM}$?
In particular, why can it not decay into lighter particles ...
- 27.2k
4
votes
2
answers
2k
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Spin-dependent and spin-independent interactions of the dark matter
What is meant by spin-dependent and spin-independent interactions of the dark matter with the nuclei?
How is the interaction between nucleus and DM modeled?
What can we conclude if the DM-nuclei ...
- 27.2k
1
vote
0
answers
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Is spacetime supersymmetry realized at TeV scale? and more questions on supersymmetry [closed]
Is spacetime supersymmetry realized at TeV scale?
If so, what is the mechanism of supersymmetry breaking?
Does supersymmetry stabilize the electroweak scale, preventing high quantum corrections?
...
user143869
6
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2
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481
views
How bad would it break physics if dark matter was not “particles”?
Some people suggest that dark matter might not even be particles at all —that’s just what physisists expect to find with reference to what they are familiar with.
But, I learned, from layman books of ...
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5
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3
answers
1k
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Most likely candidate for dark matter?
I have read into some depth about the various candidates for dark matter, the merits and flaws of each.
However what I have been unable to attain from texts alone is what is the most likely ...
- 1,720
4
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1
answer
181
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Is this article about the SMASH hypothesis a fair assessment?
New Scientist is gushing as usual about a new development in physics. This one, called SMASH, looks truly interesting, though.
Apparently it's a small extension to the Standard Model that explains "...
- 212
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2
answers
827
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Why standard model particles cannot be dark matter particles
I'm interested if any of the particles in the standard model could be potential candidates for dark matter?
I know that we do not see dark matter, therefore dark matter does not interact ...
- 141
2
votes
1
answer
355
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Signs of supersymmetry and thus dark matter at CERN
The Large Hadron Collider at CERN has just re-started after a two year pause and is now running at unprecedented levels of 6.5 TeV, with collisions that will release up to 13.5 TeV. With this increase ...
- 277
5
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1
answer
196
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Where would the dark matter particle fit inside a picture of the standard model of particle physics?
Where would the dark matter particle fit inside a picture of the standard model of particle physics?
While I am particularly fond of the Sterile Neutrino, I have not been able to find any example of ...
- 195
4
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3
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365
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Could Dark Matter particles that don't couple to quarks or leptons have been produced?
With what we know about physics, is it possible that when the universe 'began', around when quarks and leptons were produced, another particle, which doesn't couple to either quarks, leptons or ...
- 111
4
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2
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226
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Neutrino Nuclei Coherent scattering and the Dark Matter lower wall
Suppose that current and new forthcoming dark matter direct detection experiments find no evidence of Dark matter events and exclude interactions of hypothetical DM particles (like LSP or similar) in ...
- 6,727
18
votes
1
answer
878
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Dark matter and $SO(10)$ grand unification
$SO(10)$ grand unified theories nicely accommodate a massive $\sim 10^{14-15}\; GeV$ sterile neutrino. Would this be a viable dark matter candidate? I haven't found any specific material regarding ...
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